| 摘要 |
A method of accurately punching holes into a moving web of a thermoplastic film material, and more particularly, punching holes into the web through the intermediary of a rotary serrated tube punch. The invention relates to accurately punching holes into an advancing web of thermoplastic film material utilizing a novel rotary serrated tube punch. The film web is continuously advanced over at least a portion of the circumferential surface of a rotatable anvil roll, and tensioned against the anvil roll surface through the use of suitable tensioning devices, such as tension rollers arranged upstream and downstream of the anvil roll. At least one opening is formed in the circumferential surface of the anvil roll which is slightly larger than the size of the hole which is desired to be punched into the film web through the use of the inventive rotary tube punching arrangement. The rotary tube punch possesses a serrated cutting edge at its radially outermost end, and is adapted to be rotated in synchronism with the anvil roll and concurrently pivoted or tumbled, so as to cause the serrated cutting edge pierce through the web in a precisely aligned position with the opening in the rotating anvil roll, and to thereby produce an accurately dimensioned hole in the moving web without the necessity for stoping the web. The anvil roll may be constructed hollow, and communicates with a suctioning source for aspirating punched out film material segments.
|
